Patients' understanding of genetic susceptibility testing in mainstream medicine: qualitative study on thrombophilia.

Background: UK and US policy initiatives have suggested that, in the future, patients and clinicians in mainstream medicine could use genetic information to prevent common illnesses. There are no studies on patients' experience and understanding of the process of testing for common genetic susceptibilities in mainstream medicine.

Methods: Qualitative interviews with 42 individuals who had undergone testing for a genetic susceptibility for deep vein thrombosis in primary and secondary care in the UK.

Results: Some participants, often from higher social classes, had a good understanding of the test and its implications. They had often sought additional information on thrombophilia from relatives and from the Internet. Others, often from less privileged backgrounds, had a poorer understanding of the test--seven individuals were unaware of having had the genetic test. Features of genetic information led to misunderstandings: (i) at referral, (ii) when communicating results, and (iii) when making sense of the implications of testing. Participants' accounts indicated that non-specialist doctors may feel obliged to refer a patient for a genetic test they know little about, because a patient requests it after a relative had tested positive. Sometimes a referral for a genetic test was lost under information overload when multiple tests and issues were considered. The inconsistent and informal ways of communicating test results--for example by phone--in mainstream medicine also led to confusion. Participants did not generally overestimate their risk, but some were uncertain about whether they were taking the right preventive actions and/or whether their children were at risk. Information about genetic susceptibilities was difficult to make sense of, as it related to ambiguous risks for participants and family members, complicated and unfamiliar terminology and multiple genes and preventive strategies.

Conclusion: Policy visions of clinicians and patients in mainstream medicine seeking and using genetic information at their own initiative may not be realistic. Patients need more direct support in making sense of genetic information, if this information is to bring the anticipated health benefits, and not fuel health inequalities or create ethical problems. Clinicians in secondary and primary care need guidance to help them introduce genetic tests, communicate their results and explain their implications.